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      03-22-2013, 07:40 PM   #21
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Drives: '08 IB E92
Join Date: Sep 2011
Location: OC

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Originally Posted by M3takesNYC View Post
Most of this is true but does not explain why you want gas that is already at its slowest point due to being cool, near the end, want to make it even slower and not efficiently exit the system as a smaller pipe (or atleast the same size as the rest of the exhaust) would do. If the whole thing was 3 inches then fine but 2.5 and than 3 at the end. Taking slow gases there and making them even less able to exit with slower velocity due to piping, being cool and being at the end of the system so has lost a lot of kinetic energy.

I was just looking for a reason which I don't think is unreasonable when people way 2k for an exhaust. Have we really gotten to the point we defend tuning companies just because of their name without a sensible explanation?

Its lacking those standards which allow companies to just sell products that lack any real quality or testing (not saying AA does this) but clearly you guys realize this happens all the time with unsubstantiated claims and people buying a crap load of products.

Was real simple, I don't doubt its a great AA system but can someone tell me an explanation that uses physics and makes sense to go from a smaller pipe throughout to a larger pipe at the end
I did explain that, you are not thinking about it correctly. I'm not trying to be rude but I think you may not have a complete understanding of pressure and flow.

We both agree that you want to maximize flow through the engine right? To maximize flow, you want to decrease the back pressure that prevents the engine from pumping the most air that it can because reducing back pressure increases flow rate. You can reduce back pressure with smoother pipes, less bends, larger pipes/lower velocity. In this case, we are concerned with velocity. Pressure drop in a pipe is a function of velocity. Even though the flow is going slower through the bigger pipe, the flow rate will still higher because of the reduced back pressure.

I think it's reckless to accuse me of defending expensive exhausts without a sensible explanation. First of all, I am not defending them, I am trying to explain to you why you are thinking about it the wrong way. Secondly, I am an engineer and I deal with flow in pipes and ducts on a daily basis so I know a thing or two about this.

I realize that people on here defend parts just because of the name but, frankly, in this case, you are part of the problem. You are defaming AA's product and spreading false information without a clear understanding of what your criticisms are based on.
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